Search

Background: Perfluorooctane sulfonic acid (PFOS), a widely used industrial chemical, was reported to induce memory and learning process dysfunction. Some studies tried to reveal the mechanisms that mediate these effects, but how they are produced is still unknown. Basal forebrain cholinergic neurons (BFCN) maintain cognitive function and their selective neurodegeneration induces cognitive decline, as observed in Alzheimer's disease. PFOS was reported to disrupt cholinergic and glutamatergic transmissions and thyroid hormone action, which regulate cognitive processes and maintain BFCN viability. Objective/Methods: To evaluate PFOS neurodegenerative effects on BFCN and the mechanisms that mediate them, SN56 cells (a neuroblastoma cholinergic cell line from the basal forebrain) were treated with PFOS (0.1 µM to 40 µM) with or without thyroxine (T3; 15 nM), MK-801 (20 µM) or acetylcholine (ACh; 10 µM). Results: In the present study, we found that PFOS treatment (1 or 14 days) decreased thyroid receptor α (TRα) activity by decreasing its protein levels and increased T3 metabolism through increased deiodinase 3 (D3) levels. Further, we observed that PFOS treatment disrupted cholinergic transmission by decreasing ACh content through decreased choline acetyltransferase (ChAT) activity and protein levels and through decreasing muscarinic receptor 1 (M1R) binding and protein levels. PFOS also disrupted glutamatergic transmission by decreasing glutamate content through increased glutaminase activity and protein levels and through decreasing N-methyl-D-aspartate receptor subunit 1 (NMDAR1); effects mediated through M1R disruption. All these effects were mediated through decreased T3 activity and T3 supplementation partially restored to the normal state. Conclusions: These findings may assist in understanding how PFOS induces neurodegeneration, and the mechanisms involved, especially in BFCN, to explain the process that could lead to cognitive dysfunction and provide new therapeutic tools to treat and prevent its neurotoxic effects. [ABSTRACT FROM AUTHOR]

Background Per- and polyfluoroalkyl substances (PFAS) are widespread and environmentally persistent chemicals with immunotoxic properties. Children are prenatally exposed through maternal transfer of PFAS to cord blood, but no studies have investigated the relationship with childhood leukemia. Methods We measured maternal serum levels of 19 PFAS in first-trimester samples collected in 1986-2010 and evaluated associations with acute lymphoblastic leukemia in full-term offspring (aged younger than 15 years) for 400 cases and 400 controls in the Finnish Maternity Cohort, matched on sample year, mother's age, gestational age, birth order, and child's sex. We analyzed continuous and categorical exposures, estimating odds ratios (ORs) and 95% confidence intervals (CIs) via conditional logistic regression adjusted for maternal smoking and correlated PFAS (ρ ≥ ±0.3). We also stratified by calendar period, mean diagnosis age, and the child's sex. Results N-methyl-perfluorooctane sulfonamidoacetic acid was associated with acute lymphoblastic leukemia in continuous models (per each doubling in levels: ORperlog2 = 1.22, 95% CI = 1.07 to 1.39), with a positive exposure-response across categories (OR>90th percentile = 2.52, 95% CI = 1.33 to 4.78; P trend = .01). Although we found no relationship with perfluorooctane sulfonic acid overall, an association was observed in samples collected in 1986-1995, when levels were highest (median = 17.9 µg/L; ORperlog2 = 4.01, 95% CI = 1.62 to 9.93). A positive association with perfluorononanoic acid was suggested among first births (P interaction = .06). The N-methyl-perfluorooctane sulfonamidoacetic acid association was mainly limited to children diagnosed before age 5 years (P interaction = .02). We found no consistent patterns of association with other PFAS or differences by sex. Conclusions These novel data offer evidence of a relationship between some PFAS and risk of the most common childhood cancer worldwide, including associations with the highest levels of perfluorooctanesulfonic acid and with a precursor, N-methyl-perfluorooctane sulfonamidoacetic acid. [ABSTRACT FROM AUTHOR]

Background: Perfluorooctane sulfonic acid (PFOS), a widely used industrial chemical, was reported to induce memory and learning process dysfunction. Some studies tried to reveal the mechanisms that mediate these effects, but how they are produced is still unknown. Basal forebrain cholinergic neurons (BFCN) maintain cognitive function and their selective neurodegeneration induces cognitive decline, as observed in Alzheimer’s disease. PFOS was reported to disrupt cholinergic and glutamatergic transmissions and thyroid hormone action, which regulate cognitive processes and maintain BFCN viability. Objective/Methods: To evaluate PFOS neurodegenerative effects on BFCN and the mechanisms that mediate them, SN56 cells (a neuroblastoma cholinergic cell line from the basal forebrain) were treated with PFOS (0.1 µM to 40 µM) with or without thyroxine (T3; 15 nM), MK-801 (20 µM) or acetylcholine (ACh; 10 µM). Results: In the present study, we found that PFOS treatment (1 or 14 days) decreased thyroid receptor α (TRα) activity by decreasing its protein levels and increased T3 metabolism through increased deiodinase 3 (D3) levels. Further, we observed that PFOS treatment disrupted cholinergic transmission by decreasing ACh content through decreased choline acetyltransferase (ChAT) activity and protein levels and through decreasing muscarinic receptor 1 (M1R) binding and protein levels. PFOS also disrupted glutamatergic transmission by decreasing glutamate content through increased glutaminase activity and protein levels and through decreasing N-methyl-D-aspartate receptor subunit 1 (NMDAR1); effects mediated through M1R disruption. All these effects were mediated through decreased T3 activity and T3 supplementation partially restored to the normal state. Conclusions: These findings may assist in understanding how PFOS induces neurodegeneration, and the mechanisms involved, especially in BFCN, to explain the process that could lead to cognitive dysfunction and provide new therapeutic tools to treat and prevent its neurotoxic effects.

[Display omitted] • The boron-doped iron-carbon composite (Fe@B/C-2) was prepared to activate PDS for PFOS removal. • Performance on PDS activation for PFOS was evaluated. • SO 4 ·− and Fe (IV) were the primary active species during PFOS removal. • The role of B in enhancing PDS activation was detailed explored. • Pathway and mechanism for PFOS degradation were proposed. In this study, the boron-doped iron-carbon composite (Fe@B/C-2) was prepared via a simple solvothermal and secondary calcination process by using iron metal–organic frameworks (Fe-MOFs) as precursor. The obtained Fe@B/C-2 possessed abundant active sites and low iron ion leaching, and exhibited excellent performance on peroxydisulfate (PDS) activation for efficient PFOS (10 mg/L) degradation (94 %) in 60 min, with 0.2 g/L of catalyst dosage, 1.0 g/L of PDS dosage and at 5.0 of initial pH. The radical scavenging and electron paramagnetic resonance (EPR) tests demonstrated that SO 4 ·− and ·OH were the primary active species during PFOS elimination. Under the attack of these species, PFOS was first transformed into PFOA, followed by a sequential defluorination process, and lastly mineralized into CO 2 and F−. Notably, DFT results revealed that Fe species, -BC 3 /-BC 2 O structures on the carbon matrix performed crucial roles in PDS activation. The extraordinary catalytic activity of Fe@B/C-2 was attributable to the synergistic effects of Fe nanoparticles and the B-doped on carbon matrix. The doped B not only could activate the inert carbon skeleton and provided more catalytic centers, but also could accelerate the electron transfer efficiency, leading to a boost in PDS decomposition. [ABSTRACT FROM AUTHOR]

Introduction: Per- and poly-fluoroalkyl substances (PFASs) are a large, complex group of synthetic chemicals humans can be exposed to from occupational or environmental sources. In this systematic review and meta-analysis, we examined the association between PFAS exposure, particularly Perfluorooctanoic Acid (PFOA), and Perfluorooctane Sulfonic Acid (PFOS), and risk of kidney, liver, and testicular cancer. Methods: We systematically searched PubMed to identify cohort and case-control studies reported after the Monograph of the International Agency for Research on Cancer and the Toxicological Profile of the Agency for Toxic Substances and Disease Registry. We assessed the quality of the studies by using a modified version of the Newcastle-Ottawa Scale (NOS). Forest relative risk (RR) plots were constructed for liver, kidney, and testicular cancer. We conducted stratified analyses by geographic region, study design, quality score, outcome, years of publication, exposure source, and PFAS type. A random-effects model was used to address heterogeneity between studies. Results: Fifteen studies, including ten cohort studies, three case-control studies nested in a cohort, and two case-control studies were included after removing duplicate and irrelevant reports. We found an association between overall PFAS exposure and the risk of kidney cancers (RR=1.18, 95% CI =1.05-1.32; I =52.8%, 11 studies). Also, we showed an association between high-level exposure to PFAS and kidney cancer (RR=1.74, 95% CI =1.23-2.47; p=0.005) and testicular cancer (RR=2.22, 95% CI =1.12-4.39; p=0.057). There was no association with liver cancer. We found no heterogeneity by geographical region, PFAS type, study design, outcome, quality score, year of publication, or exposure source. Only two studies reported results among women. Conclusions: We detected an association between overall PFAS exposure and kidney cancer and high doses of PFAS with testicular cancer. However, bias and confounding cannot be excluded, precluding a conclusion in terms of causality. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As widely used synthetic chemicals， perfluorooctane sulfonic acid （PFOS） and perfluorooctanic acid （PFOA） are ubiquitous in the environment and the human body. Due to the extensive toxic effects and bioaccumulation of PFOS/PFOA，their impact on human health has attracted more and more attention. The absorption， distribution， metabolism， excretion and toxic effects of PFOS/PFOA in mammals are systematically summarized in this paper. Moreover，the safety limits of PFOS/PFOA are summarizes herein as well as the internal exposure levels of PFOS/PFOA in Chinese general population based on published literature in order to provide a scientific basis for PFOS/PFOA risk assessment and risk management.

Perfluorinated chemicals (PFCs) are widely used in industrial and commercial applications, leading to their release into the environment. The rapid industrialization and growing population in India make it a suitable case study to investigate PFOS contamination in environmental matrices. The purpose of this study is to investigate PFOS concentrations in river water and groundwater from several locations along the Bharathapuzha river basin and estimate PFOS intakes through drinking water. The highest PFOS level detected in the surface water is 1.3 ng/L and groundwater is 1.0 ng/L, which is significantly lower than the level of PFOS detected in major rivers of many developed countries. It is possible to attribute the low PFOS concentration to factors such as high annual precipitation, reduced industrial and municipal wastewater discharge, and relatively low emissions per capita in a region where agriculture is a major part of the economy. In addition, the daily intake of PFOS through drinking water in all age groups was below the safety threshold for cancer risk. [ABSTRACT FROM AUTHOR]

• PFBS, PFOS, and PFOA were effectively degraded at 25 °C under alkaline conditions by the UV/Sulfite. • Activation energies of decomposition and defluorination are in the order of PFBS > PFOS≫PFOA. • The second-order models were developed to describe their decomposition and defluorination. • The main reaction pathways of PFBS degradation are desulfonation, H/F exchange, and chain shortening. Reduction of persistent perfluorinated compounds (PFCs) by UV-activated sulfite (SF) has been recognized as one of the most effective advanced reduction processes (ARPs). With the UV/SF ARP, PFBS degradation reached 66.6 % at 25 °C after 6 h, while PFOS and PFOA were completely degraded within 80 and 20 mins, respectively. PFOA has the largest defluorination efficiency of 77.5 %, greater than 57.8 % for PFOS and 42.7 % for PFBS after 6 h. With the UV/SF system operated at 15, 25, 35 and 45 °C, activation energy (E a) of PFBS defluorination was determined to be 360.8 kJ/mol, larger than those of PFOS and PFOA (319.4 and 67.3 kJ/mol, respectively), which implies that PFBS is more persistent and difficult to be degraded in the natural environment. Based on the consumption of SF, secondary-order kinetics models were developed to describe the degradation and defluorination of PFBS, PFOS, and PFOA at various reaction times. Concentrations of various intermediate species were determined by liquid chromatography quadrupole time-of-flight mass spectrometry (LC/QTOF-MS) during the PFBS degradation to investigate the reaction pathways in the UV/SF ARP. The proposed reaction mechanisms for PFBS degradation include desulfonation, H/F exchange, and chain shortening via direct C − C bond cleavage. [ABSTRACT FROM AUTHOR]

The occurrence and fate of polyfluorinated compounds (PFCs) in the aquatic environment resulting from anthropogenic activities has become an emerging issue of environmental chemistry. PFCs have been detected in drinking water samples, aquatic life, human tissue, and blood serum. This is attributed to their xenobiotic attributes making them environmentally persistent, bio-accumulative, and globally distributed in water receiving bodies, posing serious health problems to aquatic life and human health. This is ascribed to PFCs' peculiar physicochemical properties of being hydrophobic and oleophobic and their removal process from wastewater streams is different from any other organic pollutants. Therefore, this review summarizes the environmental occurrence and recent developments on microbial degradation of the most detected PFCs, i.e., perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) in water bodies. The available literature suggests that PFOA and PFOS are susceptible to biodegradation by Acidimicrobium sp. strain A6, Pseudomonas parafulva strain YAB1, Pseudomonas plecoglossicidia 2.4-D, and Pseudomonas aeruginosa strain HJ4. Moreover, the current study presents a summary on phytoremediation of PFOA and PFOS as a sustainable green technology. Despite the extensive work undertaken on bioremediation of PFOA and PFOS by biological processes, the available literature suggests that a lot of work still needs to be carried out aimed at investigating the biodegradation pathway of PFOA and PFOS by both microbial species and plants. [ABSTRACT FROM AUTHOR]

Background: Reports on the association of perfluoroalkyl substances (PFASs) exposure with adolescent bone health are scarce, and studies have primarily targeted maternal serum. Objective: We evaluated the relationship between autologous serum perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) levels and bone mineral density (BMD) in adolescents. Methods: We analyzed data from 1228 adolescents aged 12-19 years in the National Health and Nutrition Examination Survey (NHANES) 2005-2010 and used multiple regression analysis to identify the relationship between serum PFOA, PFOS, PFHxS, and PFNA concentrations and total femur, femoral neck, and lumbar spine BMD, in addition to multiple stratified subgroup analyses. Results: The mean age of participants was 15 years, males had higher serum PFAS concentrations than females. The results of multiple regression analysis showed that the natural log(ln)-transformed serum PFOA, PFOS, and PFNA concentrations were negatively correlated with total femur, femoral neck, and lumbar spine BMD (all p < 0.05), and ln-PFHxS was positively correlated with total femur and femoral neck BMD (all p< 0.05). In males, ln-PFOA was negatively associated with total femur and lumbar spine BMD (all p< 0.05), ln-PFOS was associated with the reduced total femur, femoral neck, and lumbar spine BMD (all p< 0.05), while ln-PFHxS and ln-PFNA were not observed to correlate with BMD at these three sites. In females, both ln-PFOA and ln-PFOS were negatively correlated with total femur and lumbar spine BMD (all p< 0.05), ln-PFHxS is associated with the increased total femur and femoral neck BMD (all p< 0.05), and ln-PFNA was negatively correlated with total femur and femoral neck BMD (all p< 0.05), most of the associations were confined to females. The associations of ln-PFOS with femoral neck BMD and ln-PFNA with total femur BMD were more significant in those who were overweight/obese and had anemia, respectively (all p for interaction < 0.05). Conclusions: In this representative sample of US adolescents aged 12-19 years, certain PFAS were associated with lower bone mineral density, and most of the associations were confined to females. The negative effect of PFAS on BMD is more pronounced in those who are overweight/obese and have anemia. However, further studies are needed to confirm this finding. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are ubiquitous synthetic chemicals that may disrupt blood pressure controls; however, human evidence to support this hypothesis is scant. We examined the association between serum concentrations of PFAS and risks of developing hypertension.Methods: This study included 1058 midlife women initially free of hypertension from the multiracial and multiethnic SWAN (Study of Women's Health Across the Nation) with annual follow-up visits between 1999 and 2017. Hypertension was defined as blood pressure ≥140 mm Hg systolic or ≥90 mm Hg diastolic or receiving antihypertensive treatment. Cox proportional hazards models were utilized to calculate hazard ratios and 95% CIs. Quantile g-computation was implemented to evaluate the joint effect of PFAS mixtures.Results: During 11 722 person-years of follow-up, 470 participants developed incident hypertension (40.1 cases per 1000 person-years). Compared with the lowest tertile, women in the highest tertile of baseline serum concentrations had adjusted hazard ratios of 1.42 (95% CI, 1.19-1.68) for perfluorooctane sulfonate (P trend=0.01), 1.47 (95% CI, 1.24-1.75) for linear perfluorooctanoate (P trend=0.01), and 1.42 (95% CI, 1.19-1.70) for 2-(N-ethyl-perfluorooctane sulfonamido) acetate (P trend=0.01). No significant associations were observed for perfluorononanoate and perfluorohexane sulfonate. In the mixture analysis, women in the highest tertile of overall PFAS concentrations had a hazard ratio of 1.71 (95% CI, 1.15-2.54; P trend=0.008), compared with those in the lowest tertile.Conclusions: Several PFAS showed positive associations with incident hypertension. These findings suggest that PFAS might be an underappreciated contributing factor to women's cardiovascular disease risk. [ABSTRACT FROM AUTHOR]

In this research, a new approach based on magnetic electrodes has been developed for the determination of per-fluorooctane sulfonic acid (PSOF). Zinc and Titanium-based Metal-organic framework (MOF) was synthesized and used with polypyrrole as a conductive polymer for preparation of the absorbent to achieve the best performance for electrochemical application. The response of the electrode for determination of the PFOS was affected and optimized by different factors such as buffer solution, pH of the solution, amount of absorbent, extraction time of absorbent, accumulation time, as well as the Square Wave Voltammetry (SWV) instrumental parameters including voltage step, pulse amplitude, frequency and resting time. In the optimum condition, the response of the Zn/Ti/C-MOF-magnetic molecular imprinting polymer/carbon paste electrode (MOFMMIP/CPE) has increased logarithmically by increasing the concentration in the range of 0.002–165 μM by the limit of detection (LOD) of 0.7 nM. The obtained percentage of Recovery (96.00–104.14 %), Bias (– 4.00 - 4.14 %) and Relative Standard Deviation (RSD) (1.89–3.74 %) for determination of the PFOS in real and spiked tap water, river water and well water samples demonstrates that the proposed method has an acceptable precision. The comparison between the gained data by the presented method and High-performance liquid chromatography (HPLC) showed that the presented method has high accuracy. [Display omitted] • Zn/Ti/C-MOF nanocomposite was used in synthesis of conductive magnetic MIP for preconcentration the PFOS. • Electrochemical determination of PFOS in wide linear range with low LOD. • The MOFMMIP/CPE show high accuracy, repeatability, reproducibility and long-term stability. [ABSTRACT FROM AUTHOR]

The occurrence and fate of polyfluorinated compounds (PFCs) in the aquatic environment resulting from anthropogenic activities has become an emerging issue of environmental chemistry. PFCs have been detected in drinking water samples, aquatic life, human tissue, and blood serum. This is attributed to their xenobiotic attributes making them environmentally persistent, bio-accumulative, and globally distributed in water receiving bodies, posing serious health problems to aquatic life and human health. This is ascribed to PFCs’ peculiar physicochemical properties of being hydrophobic and oleophobic and their removal process from wastewater streams is different from any other organic pollutants. Therefore, this review summarizes the environmental occurrence and recent developments on microbial degradation of the most detected PFCs, i.e., perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) in water bodies. The available literature suggests that PFOA and PFOS are susceptible to biodegradation by Acidimicrobium sp. strain A6, Pseudomonas parafulva strain YAB1, Pseudomonas plecoglossicidia 2.4-D, and Pseudomonas aeruginosa strain HJ4. Moreover, the current study presents a summary on phytoremediation of PFOA and PFOS as a sustainable green technology. Despite the extensive work undertaken on bioremediation of PFOA and PFOS by biological processes, the available literature suggests that a lot of work still needs to be carried out aimed at investigating the biodegradation pathway of PFOA and PFOS by both microbial species and plants.

Aim: Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are persistent pollutants associated with adverse birth outcomes. This study aimed to identify predictors of blood PFOA and PFOS concentrations in pregnant women and to estimate their associations with birth outcomes in Brazil. Methods: We conducted a cross‐sectional study with 139 pregnant women enrolled in the pilot study of the Rio Birth Cohort Study on Environmental Exposure and Childhood Development (PIPA Project). Multiple linear regression was used to estimate associations between PFOA and PFOS with maternal predictors and birth outcomes. Results: Higher levels of PFOA were observed in women aged 16–19 and 20–39 years, while fish consumption from 0.6 to 2.0 times per week was associated with lower levels of the substance. PFOS levels were higher in women living in houses with up to four rooms but lower in those who reported passive exposure to smoking. Increased newborn length and head circumference were also associated with higher maternal levels of PFOA. Conclusions: In our study, age, fish consumption, passive smoking, and the number of rooms in the house were predictors of maternal PFAS levels. However, we did not observe significant associations between maternal plasma PFAS concentrations and birth outcomes. [ABSTRACT FROM AUTHOR]

Considering that the PFOA and PFOS are widely spread chemicals with harmful effects in human and environmental health as well as the increasing interest of the scientific community in the implications that might present especially when they co-exist, this study aims to assess their harmful impacts, both individually and as a mixture on human lymphocytes and aquatic microorganisms. The cytokinesis-block micronucleus (CBMN) assay was used to examine their potential for cytotoxicity and genotoxicity towards human cells, and Microtox assay using Aliivibrio fischeri assay was used to estimate the environmental risk. Regarding the human lymphocytes, the tested concentrations ranged between 250 and 1000 μg L−1, for all cases. PFOA increased slightly the frequency of micronuclei (MN) but without statistical significance. In the case of PFOS, our results showed a dose-dependent increase in the frequency of micronuclei which showed a statistically significant difference (p < 0.001) at 1000 μg L−1, which is the highest studied concentration. Regarding the CBPI index, statistically significant (p < 0.05, p < 0.01, and p < 0.001 respectively) differences were observed at all studied concentrations of PFOS, compared to the control. The mixture was found to be more cytotoxic and genotoxic than the individual tested compounds, causing a higher decrease at the CBPI index even in lower concentrations and increase at the MN frequencies. Aliivibrio fischeri was exposed to various concentrations in the range of 0.5 μg L−1- 20 mg L−1, for 5 and 15 min and significant increase in the inhibition percentage at the highest tested concentration of their mixture after 15 min was observed. [Display omitted] • The genotoxic and ecotoxic effects of PFOA and PFOS and their mixture were studied. • PFOS was found to be more genotoxic than PFOA. • The mixture was more cytotoxic and genotoxic than the individual compounds. • PFOA and PFOS presented very low acute effects to Aliivibrio fischeri. • Geno- and eco-toxicological studies of PFAS mixtures are of high interest. [ABSTRACT FROM AUTHOR]

Endocrine disruptors (EDs) pose a serious threat to human health and the environment and require a comprehensive evaluation to be identified. The identification of EDs require a substantial amount of data, both in vitro and in vivo, due to the current scientific criteria in the EU. At the same time, the EU strives to reduce animal testing due to concerns regarding animal welfare and sensitivity of animal studies to adequately detect adverse effects relevant for human health. Perfluorooctane sulfonic acid (PFOS) is a persistent organic pollutant that is suspected to be an ED based on academic research, however it is not identified as such from a regulatory perspective. It has previously been shown that PFOS has the potential to cause neurotoxicity as well as affect the thyroid system, and it is known that specific thyroid hormone levels are critical in the development of the brain during. In this work, the aim was to evaluate a mechanism-based approach to identify ED properties of PFOS based on the Adverse Outcome Pathway (AOP) framework and using New Approach Methods (NAMs), by comparing this approach to an ED assessment based on the currently available guidance document. An AOP network (AOPN) was generated for the thyroid modality, and AOPs leading to developmental neurotoxicity (DNT) were identified. A literature search and screening process based on the AOPN, and systematic review methodology, was performed, followed by a rigorous Weight-of-Evidence (WoE) assessment. Evidence was mapped back onto the AOPN used for the literature search, to identify possible endocrine Modes-of-Action (MoAs) for PFOS and data gaps in the two assessments. It could be concluded that PFOS fulfils the criteria for ED classification in the standard ED assessment, but not in the mechanism-based assessment. The need for quantitative information, such as quantitative AOPs, for the mechanism-based approach is discussed. The possibility of a directly neurotoxic alternative MoA was also highlighted based on available in vitro data. Opportunities and challenges with implementing AOPs and NAMs into the regulatory assessment of EDs, and assessing hazard in the Next Generation Risk Assessment, is discussed. This case study exploring the mechanism-based approach to ED identification represents an important step toward more accurate and predictive assessment of EDs based on AOPs and NAMs, and to the Next Generation Risk Assessment (NGRA) concept., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Qualitative and quantitative liquid chromatography–tandem mass spectrometry methods were developed for the analysis of perfluorinated compounds in consumer products and to examine the content of perfluorinated compounds in commercial products. In this study, 11 types of perfluorinated compounds, which were divided into perfluorinated carboxylic acids, perfluorinated sulfonic acids, perfluorooctane sulfonamides, perfluorooctane sulfonamide ethanol, and fluorinated telomere alcohols, were selected. The samples were extracted ultrasonically with methanol to confirm the efficiency of various extraction solvents and to take the appropriate extraction time. Methanol extraction was conducted for 2 h, followed by filtration and analysis by liquid chromatography–tandem mass spectrometry. This paper reports the determination of 11 types of perfluorinated compound in 300 products from 16 product lines placed on the market in four industrial sectors. The target materials used in this analysis were based on the products classified into four types: coated metal wares, textile products, leather products, and household products. Of a total of 300 products, 51 were detected above the detection limits, which accounted for approximately 17% of the products tested. [ABSTRACT FROM AUTHOR]

• Removals were 59–68% of PFOA and 66–96% of PFOS, depending on the concentrations. • Adsorption on the sludge was the main responsible of the removal, particularly for PFOS. • Loss from the system was observed, due to processes other than biological and adsorption. • The inhibition index was found equal to 14 % at 4000 ng/L concentrations. • Adsorbed pollutants were released from the sludge for less than 1 %. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the most investigated compounds in the class of perfluoroalkyl substances for their persistence and wider diffusion in the environment. However, fate and behaviour of PFOA and PFOS in the Wastewater Treatment Plants (WWTPs) have not been fully understood yet. The aim of the present study was to obtain a better understanding of the processes occurring to PFOS and PFOA in the activated sludge reactor. Several experimental tests were performed in the presence of activated sludge and sterilized sludge. PFOA and PFOS showed removals from the liquid phase from 59 % to 68 % and from 66 % to 96 %, respectively, for initial concentrations from 200 ng/L to 4000 ng/L in the presence of activated sludge. A significant fraction of the initial contaminant load was found adsorbed on the sludge, mainly in the case of PFOS. Other processes occurred, not fully identified, which were responsible of a further loss from the system. Leaching tests showed negligible release of the adsorbed pollutants from the sludge. Carbon and ammonia removal in the activated sludge reactor were not significantly affected by the presence of PFOA and PFOS. The pseudo-second order kinetic model and the Freundlich isotherm provided the best fitting of the experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Increase of PFAS level adversely affected the AD system and microbial activity. • PFOA led to higher impacts on AD performance and microbial activity than PFOS. • Archaeal group was more vulnerable to both PFOA and PFOS than bacterial group. • PFOA induced changes in microbial community by their toxicity. • PFOS induced changes in microbial community by their toxicity and functional group. Per- and polyfluoroalkyl substances (PFASs) are recalcitrant organic pollutants, which accumulate widely in aquatic and solid matrices. Anaerobic digestion (AD) is one of possible options to manage organic wastes containing PFASs, however, the impacts of different types of PFAS on AD remains unclear. This study aimed to critically investigate the effects of two representative PFAS compounds, i.e., perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), on the AD performance and microbial community structure. 100 mg/L of both PFOA and PFOS considerably inhibited the AD performance and changed the microbial community structure. Especially, PFOA was more toxic to bacterial and archaeal activity than PFOS, which was reflected in AD performance. In addition, the sulfonic acid group in PFOS affected the changes in microbial community structure by inducing abundant sulfate reducing bacteria (i.e., Desulfobacterota). This study provides a significant reference to the response of AD system on different PFAS types and dosage. [ABSTRACT FROM AUTHOR]

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), widely employed as synthetic organic materials in industrial production, have raised significant concerns due to their stability, persistence, and detrimental effects on human health and the environment. In recent years, persulfate has emerged as a promising agent for water treatment, effectively purifying water by generating sulfate radicals (SO 4 ·-) in diverse systems. This comprehensive review investigates the activation mechanisms of persulfate and evaluates the removal efficiency of PFOA and PFOS within the persulfate systems. These systems encompass thermal activation, photoactivation, chemical activation using transition-metal materials and carbonaceous materials, as well as the combining methods. The influence of the coexisting matters (Cl-, NO 3 -, CO 3 2-/HCO 3 -) and humic acid is also presented. Additionally, the main degradation mechanisms of PFOA and PFOS are also summarized. Moreover, this review identifies existing limitations and proposes prospects for enhancing the remediation of PFOA and PFOS in water using persulfate. By providing valuable insights, this study serves as a crucial reference for researchers engaged in the remediation of PFOA and PFOS in aquatic environments. [Display omitted] • This review provides a comprehensive overview of persulfate activation methods. • The activation mechanism with thermal activation, photoactivation, chemical activation using transition-metal materials and carbonaceous materials, as well as some other activation methods and the effect of coexisting matters are presented. • Degradation efficiency and degradation mechanism of PFOA and PFOS assisted by persulfate activation are identified. • The limitations and prospects for enhancing the remediation of PFOA and PFOS using persulfate in water are identified. [ABSTRACT FROM AUTHOR]

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are the major components of long-chain per- and polyfluorinated alkyl substances (PFAS), known for their chemical stability and environmental persistence. Even if PFOA and PFOS have been phased out or are limited in use, they still represent a concern for human and environmental health. Several studies have been per­formed to highlight the toxicological behavior of these chemicals and their mode of action (MoA). Data have suggested a causal association between PFOA or PFOS exposure and carcinogenicity in humans, but the outcomes of epidemiological studies showed some inconsistency. Moreover, the hypothesized MoA based on animal studies is considered not relevant for human cancer. To improve the knowledge on PFAS toxicology and contribute to the weight of evidence for the regu­latory classification of PFAS, we used the BALB/c 3T3 cell transformation assay (CTA), an in vitro model under consideration to be included in an integrated approach to testing and assessment for non-genotoxic carcinogens (NGTxCs). PFOS and PFOA were tested at several concentrations using a validated experimental protocol. Our results demonstrate that PFOA does not induce cell transformation, whereas PFOS exposure induced a concentration-related increase of type III foci. Malignant foci formation was triggered at PFOS concentrations equal to or higher than 50 ppm and was not directly associated with cytotoxicity or proliferation induction. The divergent CTA outcomes suggest that different molecular events could be responsible for the toxicological profiles of PFOS and PFOA, which were not fully captured in our study.

Perfluorooctane sulfonic acid (PFOS), a persistent environmental pollutant, has adverse effects on gestation pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) is involved in angiogenesis, metabolic processes, anti-inflammatory, and reproductive development. However, the function of PPARγ in PFOS evoked disadvantageous effects on the placenta remain uncertain. Here, we explored the role of PPARγ in PFOS-induced placental toxicity. Cell viability, cell migration, angiogenesis, and mRNA expression were monitored by CCK-8 assay, wound healing assay, tube formation assay, and real-time PCR, respectively. Activation and overexpression of PPARγ were conducted by rosiglitazone or pcDNA-PPARγ, and inhibition and knockdown of PPARγ were performed by GW9662 or si-PPARγ. Results revealed that PFOS decreased cell growth, migration, angiogenesis, and increased inflammation in human HTR-8/SVneo and JEG-3 cells. Placenta diameter and fetal weight decreased in mice treated with PFOS (12.5 mg/kg). In addition, rosiglitazone or pcDNA-PPARγ rescued cell proliferation, migration, angiogenesis, and decreased inflammation induced by PFOS in HTR8/SVneo and JEG-3 cells. Furthermore, GW9662 or si-PPARγ exacerbated the inhibition of cell viability, migration, angiogenesis, and aggravated inflammation induced by PFOS in HTR-8/SVneo and JEG-3 cells. Meanwhile, the results of mRNA expression level were consistent with the cell representation. In conclusion, our findings revealed that PFOS induced placenta cell toxicity and functional damage through PPARγ pathway.

As a family of conjugated polymers, poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) has been extensively investigated because of its high conductivity, solution processability, mechanical flexibility and transparency. However, poor chemical stability makes this conducting polymer difficult for practical application. In addition, a harsh doping condition (eg, aqueous H 2 SO 4) is required to obtain high conductivity. By employing perfluorooctane sulfonic acid (PFOSA) as a mild dopant, we were able to fabricate a PEDOT:PSS film with high conductivity (ca. 1700 S/cm) as well as significantly improved chemical and long term stability. The results of detailed spectroscopic and morphological studies show that the superhydrophobic tails and hydrophilic headgroups of PFOSA in the doped PEDOT:PSS are critical factors responsible for the improved properties of the conducting polymer. Finally, owing to its mild nature, PFOSA doping can be employed to fabricate a transparent, flexible and conducting PEDOT:PSS coated PET film. Image 1 • A highly conductive (ca. 1700 S/cm) PEDOT:PSS film with significantly enhanced chemical stability can be created by doping of PEDOT:PSS with perfluorooctane sulfonic acid (PFOSA). • Owing to its mild nature, PFOSA doping can be employed to fabricate a transparent and flexible PEDOT:PSS coated PET film. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigated the changes in reactor performances, microbial communities and functional genes in partial denitrification (PD) process under elevated perfluorooctane sulfonic acid (PFOS) stress. The results showed that PFOS significantly (P ≤ 0.001) decreased NO- 2 -N accumulation rate from 71.15 ± 1.83 % to 65.96 ± 3.97 % and increased total nitrogen removal efficiency from 25.49 ± 1.67 % to 30.90 ± 4.97 %, which indicated that PFOS addition hindered the PD process but promoted the total nitrogen removal. Excitation emission matrix fluorescence spectroscopy and fourier transform infrared spectroscopy suggested significant changes in fluorescence characteristics and functional groups of extracellular polymeric substances, especially, PFOS induced the considerable synthesis of protein-like substances. In addition, high-throughput sequencing revealed that the abundance of genus Thauera , which is responsible for the NO- 2 -N accumulation, was significantly decreased from 35.98 % to 26.00 % under PFOS stress. While the abundances of common denitrifying bacteria, such as genus Denitratisoma , SM1A02 and OLB8 , increased after PFOS exposure, which was consistent with the changes of nitrogen transition. Moreover, PICRUSt showed that the abundance of NO- 3 -N reductase genes (napA) significantly (P ≤ 0.001) downregulated from 0.02 % to 0.01 %, while NO- 2 -N reductase genes (nirK) significantly (P ≤ 0.001) upregulated by 1.97 folds after PFOS addition. These results showed that PFOS stress had a profound influence on microbial structure and the functional genes. Overall, this study demonstrated the response mechanism of PD system to long-term PFOS stress and made some contributions to the improvement in the control strategy of wastewater treatment plants (WWTPs). [Display omitted] • The impacts of elevated PFOS stress on partial denitrification was investigated. • PFOS significantly hindered the NO- 2 -N accumulation. • PFOS increased the TNRE from 25.49 ± 1.67 % to 30.90 ± 4.97 %. • PFOS decreased the genus Thauera abundance from 35.98 % to 26.00 %. [ABSTRACT FROM AUTHOR]

Although microplastics (MPs) are distributed globally in the marine environment, a great deal of unknowns relating to their ecotoxicological effects on the marine biota remains. Due to their lipophilic nature, microplastics have the potential to adsorb persistent organic pollutants present in contaminated regions, which may increase their detrimental impact once assimilated by organisms. This study investigates the ecotoxicological effects of exposure to low-density polyethylene (LDPE) microplastics (11–13 μm), with and without adsorbed contaminants (benzo[a]pyrene—BaP and perfluorooctane sulfonic acid—PFOS), in the peppery furrow shell clam, Scrobicularia plana. Environmentally relevant concentrations of contaminants (BaP−16.87 ± 0.22 μg g−1 and PFOS−70.22 ± 12.41 μg g−1) were adsorbed to microplastics to evaluate the potential role of plastic particles as a source of chemical contamination once ingested. S. plana were exposed to microplastics, at a concentration of 1 mg L−1, in a water-sediment exposure setup for 14 days. Clams were sampled at the beginning of the experiment (day 0) and after 3, 7, and 14 days. BaP accumulation, in whole clam tissues, was analyzed. A multi-biomarker assessment was conducted in the gills, digestive gland, and haemolymph of clams to clarify the effects of exposure. This included the quantification of antioxidant (superoxide dismutase, catalase, glutathione peroxidase) and biotransformation (glutathione-S-transferases) enzyme activities, oxidative damage (lipid peroxidation levels), genotoxicity (single and double strand DNA breaks), and neurotoxicity (acetylcholinesterase activity). Results suggest a potential mechanical injury of gills caused by ingestion of microplastics that may also affect the analyzed biomarkers. The digestive gland seems less affected by mechanical damage caused by virgin microplastic exposure, with the MPs-adsorbed BaP and PFOS exerting a negative influence over the assessed biomarkers in this tissue.

Abstract Background Perfluoroalkyl chemicals (PFCs) as possible cardiovascular disrupters are universally detected in humans. However, evidence from epidemiological studies appears insufficient and ambiguous. Objectives We aim to examine the serum PFCs levels and their associations with the prevalence of cardiovascular diseases (CVD) and related outcomes in general US population. Methods We investigated the serum levels of 12 major PFCs, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), 2-(N -ethyl-perfluorooctane sulfonamido) acetate (EPAH), 2-(N -methyl-perfluorooctane sulfonamido) acetate (MPAH), perfluorodecanoic acid (PFDE), perfluorobutane sulfonate (PFBS), perfluoroheptanoic acid (PFHP), perfluorononanoic acid (PFNA), perfluorooctane sulfonamide (PFSA), perfluoroundecanoic acid (PFUA), and perfluorododecanoic acid (PFDO), in 10,859 participants from the National Health and Nutritional Examination Survey (NHANES) 1999–2014. Logistic regression models were used to estimate the associations between serum PFCs and 5 self-reported CVD outcomes, including congestive heart failure, coronary heart disease, angina pectoris, heart attack, and stroke. Linear regression analyses were used to estimate the PFCs and their associations with 8 traditional CVD risk factors like serum triglyceride and total cholesterol. Results In multivariable-adjusted models, total PFCs were positively associated with total CVD (p for trend = 0.0166), independent of traditional CVD risk factors, such as smoking status, diabetes, hypertension and serum cholesterol level. Compared with reference quartile of total PFCs levels, the multivariable adjusted odds ratios in increasing quartiles were 1.23 [95% confidence interval (CI): 0.91–1.66], 1.47 (95% CI: 1.14–1.89) and 1.45 (95% CI: 1.06–1.98) for total CVD. Similar positive associations were found if considering individual PFCs including PFOS, PFUA, MPAH, EPAH, PFDO, PFSA and PFBS. In addition, serum levels of MPAH and PFDO were positively associated with congestive heart failure; PFNA, PFDE, and PFUA were positively associated with coronary heart disease; PFUA and PFDO were positively associated with angina pectoris; and PFNA was positively associated with heart attack. Conclusions Our findings suggested that exposure to PFCs was positively associated with risk of CVD. Further longitudinal studies are needed to increase our understanding about the role of PFCs exposure in the prevalence of CVD. Graphical abstract Unlabelled Image Highlights • Polyfluoroalkyl chemicals were related to risk of cardiovascular diseases (CVD). • MPAH and PFDO were positively associated with congestive heart failure. • PFNA, PFDE, and PFUA were positively associated with coronary heart disease. • PFUA and PFDO were positively associated with angina pectoris. • The associations are independent of traditional CVD risk factors. [ABSTRACT FROM AUTHOR]

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) are part of a family of perfluorinated chemicals that are used in protective coatings of all sorts. Due to their unique physicochemical characteristics, such as chemical and thermal inertness, low surface energy, and high surface-active properties, they have been used in a very wide variety of consumer and industrial applications. However, several perfluorinated compounds have been shown to be persistent, bioaccumulative, and toxic. Therefore, the determination of amounts of PFOA and PFOS in the food stuffs is very important. The information reviewed in this paper suggests that continued human exposure to even relatively low concentrations of PFOA and PFOS in foodstuffs results in elevated body burdens that may increase the risk of health effects. [ABSTRACT FROM AUTHOR]

Irradiation of aqueous suspensions containing hydrogen-terminated detonation nanodiamond (HND) with sub-bandgap (λ exc > 225 nm) excitation leads to the reductive degradation of perfluorooctanesulfonate (PFOS). As evidenced by nanosecond transient absorption spectroscopy (nsTA), we show that 254 nm excitation of HND in water induces the photoemission of electrons producing hydrated electrons (e aq -). A red shift in the e aq - absorption maximum relative to bulk water indicates a disruption in the hydrogen bonding network of the interfacial water layer at the HND surface. A shortening of the e aq - lifetime with the addition of PFOS and accompanying blue shift of the e aq - absorption maximum indicate PFOS reduction and HND/PFOS surface interactions, respectively. Prolonged photolysis of HND/PFOS solutions at 254 nm results in the degradation of PFOS into smaller polyfluoroalkyl derivatives consistent with other advanced reduction processes. The degradation of PFOS by this method is less sensitive to pH than the state-of-the-art UV-sulfite method. [Display omitted] • Sub-bandgap excitation of H-terminated nanodiamond (HND) produces hydrated electrons. • Sub-bandgap excitation of HND suspensions degrades perfluorooctanesulfonate (PFOS). • The hydrated electrons are shown to reduce PFOS. • Direct evidence is presented of PFOS interaction with HND surface. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new sensor for determination of PFOS by molecularly imprinted sensor was established. • The sensor was prepared by electrochemical polymerization using dopamine as a monomer. • Dopamine is a environment-friendly molecularly imprinted monomer compare with others. • The sensor exhibited good selectivity and repeatability. • The sensor presented excellent potential for monitoring of environmental water sample. This research aimed at developing an electrochemical sensor for the sensitive and selective determination of trace levels of Perfluorooctanesulfonic Acid (PFOS) in environmental water. The sensor (PFOS-MIPPDA/AuNPs/GCE) reported here is based on a glassy carbon electrode electrodeposition with gold nanoparticles (AuNPs) and modified with a molecularly imprinted polymer (MIP), which was prepared through the in situ electropolymerization of dopamine (DA) with PFOS as the template. Then, a new method for PFOS determination was established by differential pulse voltammetry using K 3 [Fe(CN) 6 ] as the detection probe. The optimal conditions for the preparation and analysis of the sensor were investigated. The surface morphology and electrochemical properties of the sensor were characterized by scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Results showed that the PFOS-MIPPDA/AuNPs/GCE sensor prepared by this method has good recognition performance, the linear range for PFOS detection is 0.01–8.00 µmol/L, and the detection limit is 0.0042 µmol/L. The result is satisfactory when used to analyze real water samples with recovery between 96.9 % and 104.6 %. This method has low cost, sensitive detection, and fast operation and has a potential application prospect for PFOS detection in environmental water samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • AGS removed PFOS mainly through adsorption rather than biodegradation. • PFOS deteriorated the AGS flocculation and caused its disintegration. • TN removal rate could be enhanced about 9.51 % with 5.0 mg/L PFOS addition. • PFOS altered the microbial community, resulting in changes in AGS performance. The biogeochemistry (i.e., migration and transformation) and impacts of perfluorooctane sulfonic acid (PFOS) in an aerobic granular sludge (AGS) system have been studied. The results suggested that PFOS removal rates under 0.1, 0.5 and 5.0 mg/L PFOS treatment were 89.23 ± 0.92 %, 71.92 ± 1.45 % and 48.15 ± 1.90 %, respectively, which was mainly attributed to the adsorption mechanism involving electrostatic, hydrophobic and ionic bridging interactions. Meanwhile, the adsorbed PFOS deteriorated sludge flocculation. Compared with the control, 0.1 mg/L PFOS treatment increased the concentration of effluent suspended solids (ESS) from 70 ± 5 to 238 ± 15 mg/L. Interestingly, the denitrification performance of the AGS improved (i.e., total nitrogen (TN) average removal rate increased from 87.05 ± 0.21 % to 96.56 ± 0.05 %), which was contrary to the outcomes for activated sludge. Further analysis showed that PFOS reduced the percentage of norank_f_norank_o_Ardenticatenales , norank_f_Sphingomonadaceae and Candidatus_Competibacter maintaining the particle stability, which led to the decrease in AGS flocculation. In addition, the relative abundance of nitrite-oxidizing bacteria Nitrospira decreased under PFOS exposure, while the total abundance of denitrifying bacteria (mainly Dechloromonas) increased. This might enhance the short-cut nitrification and denitrification capacity of the AGS system and promote the removal of TN. However, PFOS had no obvious impact on the settleability of AGS and the transformation of chemical oxygen demand (COD) and soluble phosphorus (SOP). Our findings will provide theoretical insights and practical support for risk control in the process of treating fluoride-containing wastewater. [ABSTRACT FROM AUTHOR]